PROJECT SUMMARY/ABSTRACT The goal of this pilot study is to examine whether aged African Americans and Caucasians differ in driving behaviors, and if so, whether these differences are linked to Alzheimer?s Disease (AD) biomarkers, as well as vascular risk factors. Our research indicates that driving decline among older adults, an important functional outcome, is predicted by preclinical AD. However, little is known about driving behavior specifically in African American older adults. Closing this knowledge gap soon is critical, since African Americans are at twice the risk of symptomatic AD compared to Caucasians. This research is significant because 36 million licensed drivers are aged 65 years or older, and the number of older adults in the United States is expected to double by 2050, when 1 in 4 drivers will be 65 years or older. Motor vehicle crashes are a leading cause of injury and death in older adults. Research on older African American drivers, to date, has only looked at driving cessation, and has not examined AD and cognition. The ability to identify who will be at most risk of driving decline and to predict when decline will occur would inform early driving safety intervention trials for older adults. Our Specific Aims will test whether AD biomarker values interact with race and vascular risk factors (VRF) in predicting driving behavior over a one-year period: (1) We will determine, among cognitively normal older adults (N=60) whether there are racial differences in driving performance and behavior while adjusting for VRF, over a one-year period. (2) We will test whether factors known to be associated with AD predict driving performance and behavior by examining the three-factor interaction between race, AD biomarkers and VRF. To test these Specific Aims, we have assembled a multidisciplinary team with expertise in AD, neuroimaging biomarkers, CSF biomarkers, driving generally, naturalistic driving specifically, cognitive and brain aging, gerontology and longitudinal biostatistical methods. We will capitalize on our parent R01 by following a subset (N=30 African American, 30 Caucasian) of cognitively normal participants with and without preclinical AD. Each participant will take part in an annual, on-road driving evaluation to measure driving performance, as well as have their driving behavior captured daily, using a naturalistic method that collects data on date, time, speed, longitude and latitude each time a participant drives their vehicle. We will test whether AD biomarker values and vascular risk factors interact with race in predicting driving performance and behavior. If the interaction between AD biomarkers and race is significant, this would stress the importance of obtaining biomarker measurements in research. These data may be valuable when seeking to explain the higher rate of AD development among African Americans, and in conducting clinical trials.